A summary of the most common chemical descriptors (InChI Key and SMILES codes) for (R)-paliperidone are summarized together with 3D and 2D structures and relevant physico-chemical properties.

What is the (R)-paliperidone?

The molecule (R)-paliperidone presents a molecular formula of C23H27FN4O3 and its IUPAC name is (9R)-3-[2-[4-(6-fluoro-1,2-benzoxazol-3-yl)piperidin-1-yl]ethyl]-9-hydroxy-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one.

Paliperidone, marketed under the brand name Invega, is an atypical antipsychotic medication. It is the active metabolite of risperidone and belongs to the chemical class of benzisoxazole derivatives. Paliperidone is a dopamine antagonist with high binding affinity for dopamine D2 and D3 receptors. It is approved by the U.S. Food and Drug Administration (FDA) for the treatment of schizophrenia..

Paliperidone was developed by Janssen Pharmaceutica. It is a stereoisomer of risperidone, and the two have similar pharmacological profiles. The (R)-isomer of paliperidone is more active than the (S)-isomer. The (R)-isomer is also the active metabolite of risperidone..

Paliperidone is metabolized in the liver by CYP3A4 and CYP2D6 enzymes. The major active metabolite is 9-hydroxyrisperidone, which is formed by CYP3A4. 9-Hydroxyrisperidone has similar pharmacological activity to paliperidone..

Paliperidone is well-absorbed after oral administration. Peak plasma concentrations are reached in 3-8 hours. The bioavailability of paliperidone is about 50%. Paliperidone is highly bound to plasma proteins (95%)..

Paliperidone is extensively metabolized in the liver. The major metabolites are 9-hydroxyrisperidone and 10-hydroxyrisperidone. Both of these metabolites are active and have similar pharmacological activity to paliperidone..

The half-life of paliperidone is about 24 hours. Paliperidone is eliminated mainly in the urine as metabolites..

Paliperidone is a dopamine antagonist with high binding affinity for dopamine D2 and D3 receptors. It is approved by the U.S. Food and Drug Administration (FDA) for the treatment of schizophrenia. Paliperidone is well-absorbed after oral administration and has a half-life of about 24 hours. Paliperidone is extensively metabolized in the liver and eliminated mainly in the urine as metabolites..

3D structure

Cartesian coordinates

Geometry of (R)-paliperidone in x, y and z coordinates (Å units) to copy/paste elsewhere. Generated with Open Babel software.

2D drawing


(R)-paliperidone PMXMIIMHBWHSKN-LJQANCHMSA-N chemical compound 2D structure molecule svg


Molecule descriptors

IUPAC name(9R)-3-[2-[4-(6-fluoro-1,2-benzoxazol-3-yl)piperidin-1-yl]ethyl]-9-hydroxy-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one
InChI codeInChI=1S/C23H27FN4O3/c1-14-17(23(30)28-9-2-3-19(29)22(28)25-14)8-12-27-10-6-15(7-11-27)21-18-5-4-16(24)13-20(18)31-26-21/h4-5,13,15,19,29H,2-3,6-12H2,1H3/t19-/m1/s1

Other names (synonyms)

IUPAC nomenclature provides a standardized method for naming chemical compounds. Although this system is widely used in chemistry, many chemical compounds have also other names commonly used in different contexts. These synonyms can come from a variety of sources and are used for a variety of purposes.

One common source of synonyms for chemical compounds is the common or trivial names, assigned on the basis of appearance, properties, or origin of the molecule.

Another source of synonyms are historical or obsolete names employed in the past, however replaced nowadays by more modern or standardized names.

In addition to common and historical names, chemical compounds may also have synonyms that are specific to a particular field or industry.

  • (+)-9-Hydroxyrisperidone
  • (9R)-3-(2-(4-(6-Fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl)ethyl)-6,7,8,9-tetrahydro-9-hydroxy-2-methyl-4H-pyrido(1,2-a)pyrimidin-4-one
  • (9R)-3-[2-[4-(6-fluoranyl-1,2-benzoxazol-3-yl)piperidin-1-yl]ethyl]-2-methyl-9-oxidanyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one
  • (9R)-3-[2-[4-(6-fluoro-1,2-benzoxazol-3-yl)-1-piperidinyl]ethyl]-9-hydroxy-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one
  • (9R)-3-[2-[4-(6-fluoro-1,2-benzoxazol-3-yl)piperidin-1-yl]ethyl]-9-hydroxy-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one
  • (9R)-3-{2-[4-(6-Fluoro-1,2-benzisoxazol-3-yl)piperidin-1-yl]ethyl}-9-hydroxy-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one
  • (9R)-3-{2-[4-(6-fluoro-1,2-benzoxazol-3-yl)piperidin-1-yl]ethyl}-9-hydroxy-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one
  • (R)-9-Hydroxy Risperidone
  • (R)-paliperidone
  • 130049-85-3
  • 29F930S8Z1
  • 4H-Pyrido(1,2-a)pyrimidin-4-one, 3-(2-(4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl)ethyl)-6,7,8,9-tetrahydro-9-hydroxy-2-methyl-, (9R)-
  • 9R-Paliperidone
  • A808242
  • A937348
  • AB01562960_01
  • AM84407
  • CCG-213028
  • DSSTox_CID_28985
  • DSSTox_GSID_49059
  • DSSTox_RID_83250
  • NCGC00183874-01
  • NCGC00186014-02
  • NCGC00389611-01
  • Paliperidone (Invega)
  • Paliperidone, (R)-
  • Q27157247

Reference codes for other databases

There exist several different chemical codes commonly used in orded to identify molecules:
  • ZINC1481956
  • CAS-144598-75-4
  • UNII-29F930S8Z1
  • DTXSID60861376
  • CHEMBL2361980
  • CHEBI:83806
  • Tox21_113609
  • Tox21_113609_1
  • SCHEMBL67205

Physico-Chemical properties

IUPAC name(9R)-3-[2-[4-(6-fluoro-1,2-benzoxazol-3-yl)piperidin-1-yl]ethyl]-9-hydroxy-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one
Molecular formulaC23H27FN4O3
Molecular weight426.484
Melting point (ºC)
Boiling point (ºC)
Density (g/cm3)
Molar refractivity118.87
Topological polar surface area84.4

LogP and topological polar surface area (TPSA) values were estimated using Open Babel software.

The n-octanol/water partition coeficient (Kow) data is applied in toxicology and drug research. Kow values are used, to guess the environmental fate of persistent organic pollutants. High partition coefficients values, tend to accumulate in the fatty tissue of organisms. Molecules with a log(Kow) (or LogP) greater than 5 are considered to bioaccumulate.

TPSA values are the sum of the surface area over all polar atoms or molecules, mainly oxygen and nitrogen, also including hydrogen atoms.

In medicinal chemistry, TPSA is used to assess the ability of a drug to permeabilise cells.

For molecules to penetrate the blood-brain barrier (and act on receptors in the central nervous system), TPSA values below 90 Å2 are required. Thus, molecules with a polar surface area greater than 140 Å2 tend to be poorly permeable to cell membranes.